<?php 
function smartDetectUTF8($string) 
{ 
     static $result = array(); 

     if(! array_key_exists($key = md5($string), $result)) 
     { 
        $utf8 = " 
             /^(?: 
                 [\x09\x0A\x0D\x20-\x7E]              # ASCII 
                 | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte 
                 | \xE0[\xA0-\xBF][\x80-\xBF]         # excluding overlongs 
                 | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2} # straight 3-byte 
                 | \xED[\x80-\x9F][\x80-\xBF]         # excluding surrogates 
                 | \xF0[\x90-\xBF][\x80-\xBF]{2}      # planes 1-3 
                 | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15 
                 | \xF4[\x80-\x8F][\x80-\xBF]{2}      # plane 16 
             )+$/xs 
         "; 

        $result[$key] = preg_match(trim($utf8), $string); 
     } 

     return $result[$key]; 
} 

function smartStrlen($string) 
{ 
    $result = 0; 

    $number = smartDetectUTF8($string) ? 3 : 2; 

     for($i = 0; $i < strlen($string); $i += $bytes) 
     { 
        $bytes = ord(substr($string, $i, 1)) > 127 ? $number : 1; 

        $result += $bytes > 1 ? 1.0 : 0.5; 
     } 

     return $result; 
} 

function smartSubstr($string, $start, $length = null) 
{ 
    $result = ''; 

    $number = smartDetectUTF8($string) ? 3 : 2; 

     if($start < 0) 
     { 
        $start = max(smartStrlen($string) + $start, 0); 
     } 

     for($i = 0; $i < strlen($string); $i += $bytes) 
     { 
         if($start <= 0) 
         { 
             break; 
         } 

        $bytes = ord(substr($string, $i, 1)) > 127 ? $number : 1; 

        $start -= $bytes > 1 ? 1.0 : 0.5; 
     } 

     if(is_null($length)) 
     { 
        $result = substr($string, $i); 
     } 
     else 
     { 
         for($j = $i; $j < strlen($string); $j += $bytes) 
         { 
             if($length <= 0) 
             { 
                 break; 
             } 

             if(($bytes = ord(substr($string, $j, 1)) > 127 ? $number : 1) > 1) 
             { 
                 if($length < 1.0) 
                 { 
                     break; 
                 } 

                $result .= substr($string, $j, $bytes); 
                $length -= 1.0; 
             } 
             else 
             { 
                $result .= substr($string, $j, 1); 
                $length -= 0.5; 
             } 
         } 
     } 

     return $result; 
} 

function smarty_modifier_smartTruncate($string, $length = 80, $etc = '...', 
                                       $break_words = false, $middle = false) 
{ 
     if ($length == 0) 
         return ''; 

     if (smartStrlen($string) > $length) { 
        $length -= smartStrlen($etc); 
         if (!$break_words && !$middle) { 
            $string = preg_replace('/\s+?(\S+)?$/', '', smartSubstr($string, 0, $length+1)); 
         } 
         if(!$middle) { 
             return smartSubstr($string, 0, $length).$etc; 
         } else { 
             return smartSubstr($string, 0, $length/2) . $etc . smartSubstr($string, -$length/2); 
         } 
     } else { 
         return $string; 
     } 
} 
?> 

